Robotic Vehicle Having Extendable Mandible Structure

ABSTRACT

A robotic vehicle is provided with an extendable arm and a mandible structure. The mandible structure includes a pair of mandibles with toothed portions that cooperatively engage such that the mandibles may be opened and closed by applying a force to only one of the pair of mandibles. The mandible structure hangs freely from the extendable arm and is balanced so that the mandible structure naturally maintains a substantially vertical orientation. In the closed position, the mandible structure defines an interior cavity suitable for securely grasping a ring.

BACKGROUND OF THE INVENTION

The present invention generally relates to robotic arms and, in arepresentatively illustrated embodiment thereof, more particularlyrelates to a specially designed extendable mandible structure for arobotic vehicle.

In the construction of small robotic vehicles which manipulate objects,one of the design challenges presented is to provide the vehicle withthe robotic arm capable of securely manipulating smooth-surfaced rings.It has been found that attempting to grab a smooth surfaced ring bypinching it with two fingers at one point along the ring is unworkable.The smooth surface of the ring can cause the ring to slip out frombetween the fingers.

In view of these design difficulties it can be seen that a need existsfor a mandible structure for a vehicle, such as a robotic vehicle, thatprovides the vehicle with enhanced ability to manipulate smooth surfacedrings. It is to this need that the present invention is primarilydirected.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side view of an illustrative robotic vehicle provided withspecially designed mandible structure embodying principles of thepresent invention;

FIG. 2 is a side view of an illustrative robotic vehicle showing in armin an extended position;

FIG. 3 is a perspective view of a mandible structure in the closedposition;

FIG. 4 is a perspective view of a mandible structure in the openposition;

FIG. 5 is a top view of a mandible structure in the closed position;

FIG. 6 is a top view of a mandible structure in the open position.

DETAILED DESCRIPTION

Illustrated in FIG. 1 is a robotic vehicle 10 having a rectangular frameportion 12 rollingly supported by a plurality of treaded wheels 16(representatively four in number) embodying principles of the presentinvention. The treaded wheels are advantageously of the type describedin co-pending U.S. patent application Ser. No. 13/588,531, whose subjectmatter is hereby incorporated by reference for all purposes. Rising fromthe frame portion 12 is a mast 18. The mast 18 supports a highlymanipulable arm 20, which is attached to the mast at a pivot point 22.Axially aligned at pivot point 22 is a gear 24. The arm 20 may berotated about the pivot point 22 to adjust its vertical elevation byactivating an electric motor (not shown) to turn gear 24.Advantageously, the reduction transmission is used to drive the gear 24such that a small and inexpensive electric motor can provide the hightorque needed to raise and lower the armed 20. The reductiontransmission also provide stability such that the arm 20 will naturallyretain any position to which it is set, without slowly falling due tothe pull of gravity.

The arm 20 includes an extendable structure comprising an outside frame26 and an inside frame 28, commonly referred to as a linear slide.Inside frame 28 is arranged to securely slide longitudinally in a trackprovided by outside frame 26. A rope and pulley system is used tocontrol the extension of the inside frame 28. Advantageously, the ropesused to manipulate the extension of inside frame 28 loop around pivotpoint 22 and wound around an axle connected to an electric motor on mast18. Locating the drive motor for controlling the extension of insideframe 28 on the mast 18 reduces the weight of arm 20.

Coupled the inside frame 28 edit pivot point 30 is flip-out arm 32. Astring tethered to flip out arm 32 allows the flip out arm 32 to bepulled into linear alignment with outside frame 26 and inside frame 28.The string is preferably connected to an electric motor or servo on mast18.

On the flip out arm 32, at the end opposite to pivot point 30, is amandible structure 36 that freely swings about wrist pivot 34. Thestructure of mandible structure 36 is further explained below.

In one embodiment, the entire robotic vehicle 10 as illustrated in FIG.1 is dimensioned to fit within a cube measuring 18 inches per side.

Turning now to FIG. 2, illustrated is the same robotic structure as inFIG. 1 but now with flip out arm 32 linearly aligned with inside frame28 and with the inside frame 28 in its extended position. The arm 20 hasbeen partially raised by pivoting about pivot point 22. The mandiblestructure 36 hangs freely from the wrist pivot 34. As shown, themandible structure 36 is balanced such that it hangs substantiallyvertically. In this way, the mandible structure automatically positionsitself appropriately to grasp rings which may be hanging from a peg.

In one embodiment, the robotic vehicle 10 is full of lifting themandible structure 36 and retrieving a ring from a peg more than 5 feetin the air.

Turning now to FIG. 3, illustrated is a detailed perspective view of themandible structure 36. The mandible structure 36 includes a base plate40. The base plate 40 is a substantially T-shaped plate and ispreferably cut from a flat plastic material, such as Lexan. Secured tothe backside of base plate 40 is a servo motor 42. The servo motor 42 iscoupled to base plate 40 and to a set of right-side mandibles 48. Anaxle 46 is positioned on the base plate 40 opposite the servo motor 42.Coupled to the axle 46 are a set of left-side mandibles 50.

Each right side mandible 50 is a minor image of each left side mandible48. The mandibles are generally a semicircular design such that a rightside mandible and the left side mandible together (in the closedposition illustrated in FIG. 3) define a generally circular opening.Each mandible has a toothed portion at one end and a pincer portion atthe opposite end. The toothed portions 49,51 of the right- and left-sidemandibles 48 and 50 are cut so that they mesh together as the mandiblesrotate about the axle 44 and servo motor 42, respectively. Thus thetoothed portion is analogous to an arc of a gear whose centerpoint is atthe location of the axle. The mandibles are preferably cut from alightweight plastic, such as Lexan.

In the illustrated embodiment, there are three right-side mandibles 48and three left-side mandibles 50. In general, the number of left sidemandibles and right side mandibles should be equal, but more or fewermandibles are possible. Increasing the number of mandibles allows themandible structure 36 to grip a greater number of rings simultaneously.With the number of mandibles shown in FIG. 3, the mandible structure 36is capable of grasping two rings simultaneously.

The left- and right-side mandibles 48 and 50 are spaced apart along axle44 and away from servo 42 using spacers 52. Toothed spacers 53 mayoptionally be employed to provide spacing and additional gear engagementalong the toothed portions of the right-side and left-side mandibles 48and 50. The spacers 52,53 and any two adjacent left- and right-sidemandibles 48 and 50 roughly define an interior cavity 54 suitable forsecurely grasping and storing a ring. Thus the mandible structure 36includes space for a ring in the interior cavity 54 defined the bottomleft-side mandibles 48, middle left-side mandible 48, the spacersbetween the bottom and middle left-side mandibles, bottom right-sidemandible 50, middle right-side mandible 50, and the spacers between thebottom and middle right-side mandibles. Similarly, the mandiblestructure 36 includes a space for a ring in the interior cavity 54defined by the middle left-side mandible 48, top left-side mandible 48,the spacers between the middle and top left-side mandibles, middleright-side mandible 50, top right side mandible 50, and the spacersbetween the middle and top right-side mandibles.

As previously noted, the right side mandibles 48 are coupled to servomotor 42. Thus, as the servo motor 42 turns, the right side mandiblesrotate around the axis of the servo. The toothed portions of right sidemandibles 48 engage with the toothed portions of the left side mandibles50, causing the left side mandibles 52 similarly rotate about axle 46.As the right side mandibles 48 and the left side mandibles 50 rotateabout their respective axis, the pincer portions of the mandibles moveapart and the interior cavity 54 expands. The mandible structure 36 inthe open position in FIG. 4. By turning the servo motor 42 in theopposite direction, the right side mandibles 48 and the left sidemandibles 50 again rotate about their respective axis but in an oppositedirection, bringing the pincer portions back together and enclosing theinterior 54.

By selectively opening and closing the mandible structure 36, incombination with moving the vehicle 10, an operator is able position themandible structure 36 around one or more rings. When the mandiblestructure 36 is closed around a ring positioned within the interiorcavity 54, the mandible structure 36 securely grasps and stores the ringsuch that the ring cannot slip out. Because the mandible structure 36completely envelops the ring, the mandible structure 36 can grasp verysmooth surfaced rings that would be difficult to grasp by pinching themat a single location about the ring.

The foregoing detailed description is to be clearly understood as beinggiven by way of illustration and example only, the spirit and scope ofthe present invention being limited solely by the appended claims.

What is claimed is:
 1. Robotic vehicle apparatus comprising: a platformincluding a plurality of wheels; a mast attached to and verticallyrising from the base; an arm pivotally attached to the mast, the armincluding an inner frame and an outer frame whereby the inner frame isselectively extendable relative to the outer frame; and a hand attachedto the arm, the hand comprising: a base plate; a servo motor; an axle; afirst plurality of spaced mandibles attached to the servo motor; asecond plurality of spaced mandibles attached to the axle; and whereinthe first plurality of spaced mandibles and the second plurality ofspaced mandibles cooperatively engage through mutually enmeshing teeth.2. The robotic vehicle apparatus of claim 1 wherein the first pluralityof spaced mandibles and the second plurality of spaced mandibles have anopen position and a closed position.
 3. The robotic vehicle apparatus ofclaim 2 wherein: when the first plurality of spaced mandibles and thesecond plurality of spaced mandibles are in the closed position, thefirst plurality of spaced mandibles and the second plurality of spacedmandibles define a substantially circular cavity.
 4. The robotic vehicleapparatus of claim 3 wherein: the circular cavity is suitable forgrasping an annular object.
 5. The robotic vehicle apparatus of claim 4wherein: the annular object is a smooth surfaced ring.
 6. The roboticvehicle apparatus of claim 1 wherein: the first plurality of spacedmandibles and the second plurality of spaced mandibles are of a plasticmaterial.
 7. The robotic vehicle apparatus of claim 1 wherein: the handis attached to the arm through a flip-out arm.
 8. The robotic vehicleapparatus of claim 1 wherein: the hand is capable of grasping more thanone ring simultaneously.
 9. The robotic vehicle apparatus of claim 1wherein: the first plurality of spaced mandibles are spaced apart usinga plurality of spacers.
 10. The robotic vehicle apparatus of claim 9wherein: the second plurality of spaced mandibles are spaced apart usinga plurality of spacers.
 11. A robotic apparatus comprising: a base plateattached to and hanging from a pivot point; a plurality of mandiblesattached on one side of the base plate; a motor attached on an oppositeside of the base plate from the plurality of mandibles, the motoroperable to open and close the mandibles; wherein the weight of theplurality of mandibles and the weight of the motor are substantiallybalanced such that the plurality of mandibles hang in a substantiallyvertical position when the base plate is supported solely from the pivotpoint.
 12. The robotic apparatus of claim 11 wherein: the plurality ofmandibles is spaced apart using spacers.
 13. The robotic apparatus ofclaim 12 wherein: the plurality of mandibles of spaced apart defines acavity for securely holding a ring.
 14. The robotic apparatus of claim11 wherein: the base plate hangs from an arm attached to a movableplatform.
 15. The robotic apparatus of claim 11 wherein: the pluralityof mandibles includes a plurality of left side mandibles and a pluralityof right side mandibles.
 16. The robotic apparatus of claim 15 wherein:the plurality of left side mandibles include teeth that engage withteeth on the plurality of right side mandibles.
 17. The roboticapparatus of claim 16 wherein: the plurality of mandibles can be openedand closed by applying a force to only one selected from the groupcomprising: the left side mandibles and the right side mandibles. 18.The robotic apparatus of claim 16 wherein: the teeth on the left sidemandibles are arranged in a circumferential arc whose centerpointdefines an axis of rotation of the left side mandibles, and the teeth onthe right side mandibles are arranged in a circumferential arc whosecenterpoint defines an axis of rotation of the right side mandibles. 19.The robotic apparatus of claim 11 wherein: the motor is a servo motor.20. An apparatus comprising: a means for grasping a ring; a means forraising and lowering the means for grasping; a means for moving themeans for raising and lowering.